Don’t use that straw for mulch

December 14, 2017

Q: I have two straw bales left over from Halloween. Can I spread them over my vegetable garden for mulch?

A: I would not do that. They very likely are filled with weed seeds, especially the tenacious witch grass, and will gift you with a whole new crop of weeds. It is better to compost them first, in a nice, hot compost bin, to kill the weed seeds.

I understand few people keep an active, hot composting bin, so here is another idea for using them. You can place them on the garden intact, and start working some soil down into them. Scatter garden soil over the top and water it down in; repeat until they are as full of soil as you can get them.

In the spring, plant them with spinach, kale and lettuce, or wait until late May and plant tomatoes, eggplant or peppers in the bales. Keep them moist and enjoy the harvest. This will cause hidden seeds to germinate in the bale, where they can be pulled easily, and break down the straw so it can be spread on the garden later.

Q: I have been growing Mexican butterfly milkweed for monarchs. I love that it grow easily and they reseed themselves to come back each summer. But now I am reading that these are not the right butterfly weed and actually are hurting the monarchs. Is this something you can look into?

A: This is something I have looked into, and I have had a great discussion on the topic with Trevor Edmonson, a local native plant specialist. Here’s a rundown.

There are several native butterfly milkweeds; they include the bright orange Asclepias tuberosa that grows on prairies, a wet prairie plant called swamp milkweed (A. incarnata ), a wispy roadside and margin milkweed (A. verticillata) and the roadside weed with big pods that we simply call milkweed (A. syriaca). All of these attract and nurture the monarch butterfly. In fact, they are dependent upon it for survival.

The non-native Asclepias curassavica, or Mexican milkweed, grows in warmer, semitropical areas. In those warmer climates, this milkweed keeps blooming all winter. This has been presented as a problem for monarchs as it is thought the butterflies keep feeding and fail to migrate. Trevor sent me an article regarding this problem: https://entomologytoday.org/2015/01/16/planting-the-wrong-kind-of-milkweed-may-harm-monarch-butterflies.

Another problem is continuous use of the same plants causes a build-up of the plant phytols that leads to Ophryocystis elektroskirrha, a butterfly disease. Between the failure to migrate and the infections, somewhere between 10 and 20 percent of the monarch population in coastal California, Texas and Florida were suffering.

My reaction to this is simply that it isn’t a problem here as the plants stop blooming in cold weather and die. Trevor feels there is still a risk of monarchs staying too late in the season, since these milkweeds do bloom a few weeks longer than the native milkweeds.

Personally, I think these are fine contributions to the natural bridges of food we need to provide for monarchs, and they are far easier to grow than the site-fussy natives. I also feel we can pull them out easily if they continue to bloom past late summer.

Trevor also points out native plants offer benefits to the entire ecosystem and not just the monarch. I say that is true if the plants are in the matrix, or plant community, that they belong in and less true in my backyard. We agree the subject needs more research. He likes the prairie milkweed, Asclepias tuberosa for monarchs, and I like roadside milkweed, Asclepias syriaca. The roadside milkweed may reseed freely, but any unwanted plants are very easy to pull or share. So, you can see where we stand, and you must decide for yourself if there is a risk in growing Mexican milkweed.

Q: I have been given a beautiful bird-of-paradise plant. The former owner says it never bloomed for her. How can I make it bloom?

A: I’m not sure you can. They need a lot of full sun to bloom. A south window, supplemental light from a grow light and keeping it potbound might help induce it to flower. You also can try keeping it outdoors in the summer and bringing it inside in late October. That summer in the sun might trigger flowering.